Any indication of travel through one door more than the other?

It looks like both other doors see a lot of traffic.  There is almost no dust and a well-worn path between them.

T'laren, irritated at getting stuck at the back unable to do anything last time, moves to the north door and checks the handle. He gives a shrug at the others, and if no one objects, he'll try to open in.

Keashirryl will stay back while T'laren tries the door, and keeps an eye on the skeletons. They aren't usually trouble, but better safe than sorry, she thinks to herself.

Perception (if needed): 20  

Droknin’s mane on his back stands slightly, and someone close would hear his paws tightening his weapon. The Leonin is clearly not comfortable in a sanctuary reserved for the dead. He lets out a low growl, and shows some of his canines on the side. He sniffs the air, and he tries to determine if the skeletons are real or just props that silly humans display in weird places.

(Not sure if a character can do this, but here it goes if allowed.) Perception: 3

Garrin shakes his head. "The dead are best left alone."

As T'laren moves toward the northern door, the three skeletons twitch and rattle as though coming alive.  Yet when Keashirryl enters the room in her red cloak, they settle back into endless quiet.

Looking on the other side of the door, T'laren sees a 15' long hallway, another closed door at the end.

T'laren, heart slowing as the skeletons settle, will move to the other door and try it.

Seeing that the skeletons start to move, Cassius steps back but moves to ready his staff to smash the bones apart if any signs of movement are shown.

The dead remain motionless.

When T'laren moves to the end of the short hall and tries the door, he finds that it is locked.

[Also, just noticed Garrin's post #459.  Tasting the potion, he deduces that it is a potion of invisibility.]

Garrin holds up his finger and sticks out his tongue. "I've always wanted to know if that made my tongue invisible? It's an invisibility potion."

"This one's locked. Head down the unlocked on first, or we want to try to pop this one?", T'laren asks quietly.

Cassius walks to the locked, reaching into his pack for a leather case of tools. He carefully unfurls and sets it down to reveal a long unused set of Thieves Tools. With what was once practiced ease he pulls out a set of lockpicks and moves to kneel in front of the door. "Hope I remember how to do this..."

Lock Pick: 18

It isn't easy, but Cassius is able to work the mechanism in the lock until it clicks open.  Pushing the door open, you see that racks of weapons line the walls of this chamber, including spears, swords, crossbows, and bolts. A dozen dirty red cloaks hang from hooks by the door.  It looks like you have found their armory.  The weapon racks hold twelve spears, six shortswords, four longswords, six light crossbows, and eight quivers holding twenty crossbow bolts each.  

((I suspect the cloak is what keeps the skellies quiet from how you worded it, but would it be reasonable for the party to suspect the same?))

[Perhaps.  They were clearly stirring, and clearly stopped once Keashirryl entered the room.  So it might be reasonable to guess that one of the following played a role:

• The fact that she is a tiefling
• The fact that she is a cleric
• The fact that she was wearing a red cloak]

((Kinda what I was thinking.))

"Are you a necromancer? No judgment, I'm grateful you can keep the dead at rest... Though if you can convince them to rise up and go after the Redbrands, that'd be a big advantage.", T'laren remarks to Keashirryl.

Keashirryl turns sharply towards T'laren, then takes a deep breath, and hits a not too unfriendly voice. 

"I'm not. Not any more. It is a long story, but I have burnt my spellbook some time ago, and I can't do too much raising without that," she shrugs. "I honestly don't know what calmed them. I suspect the cloak." 

"Ah. Interesting. Well, whatever the reason, sticking close to you seems wise. Though if we were to take these cloaks, even if they don't soothe skeletons, might give any Redbrands pause."

When the skeletons begin to twitch and rattle, Droknin's mane becomes fully erect, and he takes a half step back. He opens his mouth showing all his sharp canines, and hisses loudly at the undead abominations. Then the skeletons settle down, and Drokin looks puzzled at them.